Originally Posted by
MrDplus
Thanks. That's what I'm doing in Singapore, but I don't think I can do it in Bangkok since I'm not staying at any hotel. I arrive in the morning and leave at midnight.
My last resource would be to appeal to the generosity of the people at the TG F Lounge.
The post office in the back of the BKK check in hall (4th floor/far south-west corner) is open 24/7. Just use that.